I. Field of the Invention
The invention refers to a heat exchanger device for heating up a liquid, which preferably is water, in a container or boiler. The container comprises heat transfer tube means, through which a heating fluid as e.g. steam, hot water from a central heating or freon from a heat pump is guided, and which transfer the heat of the heating fluid to the liquid in the container. The heat transfer tube means are e.g. coils of pipe having a big heat transfer surface.
II. Description of the Prior Art
Heat exchanger devices of the above kind are known e.g. from German publication No. 30 05 858. Such known heat exchanger devices need a relatively long heating up time, especially for containers of large volume, before the water temperature reaches the desired level of say 60.degree. to 80.degree. C. In the meantime the user has to content himself with water of lower temperatures. In order to eliminate this drawback efforts have been made to reduce the heating up time by a more efficient heating process as e.g. by induced liquid circulation within the container. However, the heating up time for big containers is still too long, which is especially disturbing if there is momentary need for little volumes of hot water.